1.\" $OpenBSD: fdc.4,v 1.3 2000/09/09 17:15:56 deraadt Exp $ 2.\" $NetBSD: fdc.4,v 1.6 1996/03/22 01:55:14 andrew Exp $ 3.\" 4.\" Copyright (c) 1996 Andrew C. Wheadon 5.\" Copyright (c) 1983, 1991, 1993 6.\" The Regents of the University of California. All rights reserved. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" @(#)fdc.4 8.1 (Berkeley) 3/22/96 37.\" 38.Dd March 25, 1996 39.Dt FDC 4 40.Os 41.Sh NAME 42.Nm fdc 43.Nd NEC765 compatible floppy disk driver 44.Sh SYNOPSIS 45.Cd "fdc0 at isa? port 0x3f0 irq 6 drq 2" 46.Cd "fd* at fdc? drive ? flags Z" 47.Sh DESCRIPTION 48The 49.Nm 50driver supports the standard AT floppy disk controllers. 51These include standard IDE, MFM, RLL, 52EIDE, ESDI, and SCSI controllers with floppy attachment. 53.Pp 54The standard names of a floppy drive will take the form 55.Nm /dev/fd{0,1,2,3}{,B,C,D,E,F,G,H}[abcdefghijklmnop] . 56.Pp 57The first component of this path is the unit number, permitting 58a total of 4 floppy drives. 59The next component is missing for the default geometry (it 60would be A, but it is omitted for simplicity) and B-H for the 61other 7 geometry types the floppy driver supports. 62The last component of the path is the 16 partitions that a floppy 63disk can support. 64.Pp 65The additional geometry types are as follows: 66.Pp 67.Bl -tag -width xxxxxx -offset indent -compact 68.It `B' 1.44MB 69.It `C' 1.2MB 70.It `D' 360KB/AT (360KB disk in a 1.2 MB drive) 71.It `E' 360KB/PC (360KB drive) 72.It `F' 720KB 73.It `G' 720KB/x (720KB in a 1.2 MB drive) 74.It `H' 360KB/x (360KB in a 720KB drive) 75.El 76.Pp 77The default geometry is the format specified in the BIOS, and 78is typically the largest supported format. 79.Pp 80Some floppy controllers do not respond correctly to probes, and 81the configuration file 82.Cm flags 83field can be used to specify a particular drive type, overriding the 84probed type. 85If the 0x10 bit is on, the low order three bits of the 86.Cm flags 87field encode the drive type, as follows: 88.Pp 89.Bl -tag -width xxxxxx -offset indent -compact 90.It 1 2.88MB 91.It 2 1.44MB 92.It 3 1.2MB 93.It 4 720K 94.It 5 360K 95.It 6 1.2 MB japanese format 96.El 97.Pp 98If the 0x20 bit is on, the drive will be attached even 99if it was not found by the probe routine. 100.Sh SEE ALSO 101.Xr intro 4 , 102.Xr dmesg 8 103.Sh BUGS 104The 105.Nm 106driver can interfere with other controllers, namely some WD/SMC 107network controllers fail to work when the probing mechanism 108in the 109.Nm 110driver probes for a missing second floppy drive. 111In this case you should try recompiling the kernel 112replacing the relevant line with 113.Cd "fd0 at fdc? drive ?". 114